Simplify the following expression: $4\sqrt{112}$.
Explanation: First, try to factor a perfect square out of the radical. $= 4\sqrt{112}$ $= 4\sqrt{16 \cdot 7}$ Separate the radical and simplify. $= 4\sqrt{16} \cdot \sqrt{7}$ $= 4 \cdot 4 \cdot \sqrt{7}$ $= 16\sqrt{7}$